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Written Testimony of Stewart Prager, Director, Princeton Plasma Physics Laboratory, Professor of Astrophysical Sciences, Princeton University
Delivered to the Committee on Science, Space and Technology Subcommittee on Energy For the hearing on April 20, 2016 Read more

(Photo by Elle Starkman/Office of Communications)Imène Goumiri led the design of a controller.

Imène Goumiri, a Princeton University graduate student, has worked with physicists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) to simulate a method for limiting instabilities that reduce the performance of fusion plasmas. The more instabilities there are, the less efficiently doughnut-shaped fusion facilities called tokamaks operate. The journal Nuclear Fusion published results of this research in February 2016. The research was supported by the DOE’s Office of Science. Read more

(Photo by J.S. Hu )Photo of white-hot limiter glowing in contact with the plasma during an EAST discharge.

Scientists at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) have helped design and test a component that could improve the performance of doughnut-shaped fusion facilities known as tokamaks. Called a “liquid lithium limiter,” the device has circulated the protective liquid metal within the walls of China’s Experimental Advanced Superconducting Tokamak (EAST) and kept the plasma from cooling down and halting fusion reactions. The journal Nuclear Fusion published results of the experiment in March 2016. The research was supported by the DOE Office of Science. Read more

The world of fusion energy is a world of extremes. For instance, the center of the ultrahot plasma contained within the walls of doughnut-shaped fusion machines known as tokamaks can reach temperatures well above the 15 million degrees Celsius core of the sun. And even though the portion of the plasma closer to the tokamak’s inner walls is 10 to 20 times cooler, it still has enough energy to erode the layer of liquid lithium that may be used to coat components that face the plasma in future tokamaks. Scientists thus seek to know how to prevent hot plasma particles from eroding the protective lithium coating. Read more

The electric current that powers fusion experiments requires superb control. Without it, the magnetic coils the current drives cannot contain and shape the plasma that fuels experiments in doughnut-shaped tokamaks correctly. Read more

10 Facts You Should Know About Plasma

It’s the fourth state of matter: Solid, liquid, gas, and plasma. Plasma is a super-heated gas, so hot that its electrons get out of the atom’s orbit and roam free. A gas thus becomes a plasma when extreme heat causes its atoms to shed their electrons. Read more

Physicists Luis Delgado-Aparicio and Egemen Kolemen of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have won a national scientific competition to conduct a full day of experiments on the DIII-D National Fusion Facility that General Atomics operates in San Diego for the DOE. The honor, known as the Torkil Jensen Award, is named after the late and internationally recognized scientist who was a member of the General Atomics Fusion Group for 44 years. Read more

A cross-section of the virtual plasma showing where the magnetic field lines intersect the plane. The central section has field lines that rotate exactly once.

A team of physicists led by Stephen Jardin of the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL) has discovered a mechanism that prevents the electrical current flowing through fusion plasma from repeatedly peaking and crashing. This behavior is known as a “sawtooth cycle” and can cause instabilities within the plasma’s core. The results have been published online in Physical Review Letters. The research was supported by the DOE Office of Science. Read more